Crane



July l, 1930- 'I G. NIEMANN 1,769,750

' CRANE Filed Oct. 31, 1927 2 Sheets-Sheet l July l, 1930.

G. NIEMANN CRANE Filed Oct. 3l, 1927 2 Sheets-Sheet Fig.4.A

Fig.4.

Inventor Patented July 1i, 1930 l UNITED STATES GUSTAV'NIEMANN, OF DUISBURG, GRMN'Y CRANE Application led October 31, 1927-, Serial No. 230,049, and in Germany April 28, ,1927.

The jib crane of the invention differs from' other cranes of its type by the simple manner' in which the horizontal movement of the load and the balancing of the weight of the jib are attained. According to the invention, a simple guide member moving alongv the uiding curved or vcam facedur-f ing the lu ng movement, the curvature of the cam face being such that, by reason of the movement of the pulley, the loa-d moves along an exactly horizontal plane and at the same time the weight of the jib is approximately orexactly balanced.

According to the invention, again, the movement of the ulley and of the counterweight may be e ected independently, that is to say, there may be provided Ia guide member and a curved guiding or cam face on the jib for the pulley,vand a separate set -of these elements for the counter-weight. The weight may be movable with respect to the guide member 'and finally the curved guiding or. cam face may at the same time serve as a part of the luling mechanism.

Several constructions of craney according to the invention are illustrated, byway of example, in the accompanying diagrammatic drawings.

Figure 1 is an elevation of a crane provided with a 'simple pivoted guide member. Figure 2 is a side elevation of 'a crane provided with a counter-weight which is movable upon the guide member.

Figure 3 is a side elevat ,n of avcrane having two separate guide members. L Figures 4 and 4a are side elevations-of cra-nes rovided with guide members which serve algo to form partv of the luliing gear.

The crane according to Figure 1 is provided with a revolving frame 1, upon which is supported thefjib 2, `which moves about the axis 3. The curved guiding or cam face 5 is disposed 'at the rear endY 4; of the j ib.

F urthermoreythe revolving frame isprovidedwith a pivotal axis 8, about which the guide member 7 revolves. T helatter is provided at its upper end with a pulley 10 for the load rope 11 and with'a counter-weight 12, and it is guided by rollers 6 on the curved guiding or cam face 5 of the jib. 6o The rope passes from the drum 13, over the pulley 10, thence to the pulley 2agat the extreme end of'the jib, and then vertically' downwards tothe load hook 11a. If the jib' 2 is luffed, the pulley 10 and the guide mem- 65 ber 7 move from the position shown in dotted lines in the drawing into the positionshown in full lines, and the load rope is sl'ackened in such manner that the'lo'ad moves on an exactly horizontal plane.

With such a lufling movement, `the centre of gravity of the jib is raised, but at thesame time the counter-weight 12 falls so that the luiiing motor has little work to do, other than overcoming friction.

The neutralization of the tipping moment of the `crane with reference to the plane I .A-B is assisted by the counter-weight since this approaches or recedes from the plane A- B at the Sametime as the jib, but re- SQ mams always at the opposite side of lthe plane A-B to that occupied by the jib.

In 'Figure -1 the counter-weight is ar- Aranged onthe axis ofthe rollers 6, the free end of the guide memberresting uponl the curved guiding or cam face 5. Such free end may, however, be disposed upon an extension of the guide member in front or to the rear of these rollers, as also at a distance from them laterally. The counter-Weight 12 may be movably provided on the guide member 7, as shown in Figure 2. In lthis case it rests upon the-slide or track 25 or the like, and is 'suspended from a rope retainingmember 26, which is pivot-ed tothe jib 2 at 9b 28. The rope 26 or retaining member is.' guided over a pulley 27 fixed to the l,guide member 7. For the rest, the numerals indicated in Figure 1 apply also to Figure 2. It will be noted, however, that in this construction the loadrope passes from the drum, 13

- 3 ofthe jib before passin first over a guide pulley on the pivotal axisfle'y, 10 and that the curve 'guiding or cam face 4 is of a somewhat different shape. Instead of the rope retaining member being fastened to the ]ib, it may be fastened to the fixed frame ofthe crane, for example, to the pivotal axis 3 ofthe jib. The track for the counter-weight on the guide member ma also be curved toany desired form'in 'or er to ensure that the counterJweight shall the jib system. In this way theA jib move-y ment-is undercomplete control, and the mo the desired position with respectto occu P through the lufling movement.

the. ib'

" I itbe desired to secure thesame exact#- ness with the'balancing of' the weight as with the horizontal path taken by the load, it is advisable to employ` two separate guide members as shown in Figure 3L The guide, member 7 in this case carries only the' pulley 10, and it is supported upon the curved guiding or camface 5 as in the construction already .referred to.

There is, however,still"a further guide member 26, whichI is supported upon a second curvedguiding or-oam face l on the jib and lwhich inv turn supports thecounterweight 12. The curved guidingor cam face `25 is so determined that the counter-weight falls, in every moment ofv time, through a distance corresponding tot-he lift of the jib. In this arrangement the' opposing 'weights may be made to balance so' exactly-that there are no 4forces of reaction of the. `jib acting upon the lufiin motor, because'they 'can be kept smaller t an the frictional forces' of tor may forV example, be constructed, as is an ordinary main current motor, without the, fear that its speed of rotation will vary con- -sderabl ,as 1s the case when the balancing of wei ts is inexact.: 1 v In `igures 1, 2.afnd 3 the lulling mechanism has been omitted for the sakeA of clearnesss;- ItA may, however, consistof a spindle drive, crank drive, or the -like'as is usual in lufling cranes.

' connectlon wlth the guiding curved or cam Ihe drive for the drawing-in mechanlsm itself is advantageously 'disposedin face on the `jib' in such manner that the curved or cam face, or th'e rear end lof the vjib is provided witha rack, into' which en gages a gear wheel on the guide member. uch a drive is illustrated in Figure 4, which for the rest shows the same crane as the Afigures of' the' drawings-hereinbefore described.

The luing motor -14 drives the vertical.

shaft 16 through a wormgear 15, and the gear wheel 17 .is mounted on it at its upper end: It engages in-a gear wheel 18 upon the axis of rotation ,8 of the guide member1 7, which vin ,turn drives the gear wheel 19 upon the shaft 20. y'This shaft is mounted fon' the guide member 7 and carries a gear wheel 21, which engages in' a bevel gear. wheel 22. The wheel 22 engages in- -a further gear -wheel 23, which in turn engages in a rack 24 on the curved guiding or cam face 5. The guide member 7 is thus 'at the same time employed asia carrier 'for As will ge seen from Fi re Ll,'the lufng motor 14 may be provield on the guide member uitself, 1n- Which construction it drives the Yspindle 20 direct. In the ex- 1 ample illustrated this spindle, by means of 'the nut 28, at 'the saine time moves the counter-weight 12, which moves relatively to 1 theA guide member in the manner re- `quired to attain the desired object. In-

lower end to the supporting rame, a guiding surface of camlike form mounted -upon the jib adjacent -the lower end, a guide.

member pivoted to the supporting frame'to the rearsof the jib and carrying the movablepulley over -which the load rope is led, the said guide member engaging the guiding surface of the jib.

2. A jib crane, as set forth in claim 1, comprising rollers by which the guide member travels upon Athe guiding surface of the jib, the movable pulley being mounted upon the axis of the said'rollers.I

f3. A jib crane as set forth in claimV 'comprising a counterwei ht whichs moved ,by thev guide member or the purpose ofA balancing the weight of the jib.

4. A 11b crane according to claim 1,'comrising rollers carried by the guide memer and'engaging vthe guiding'surface ofthe j ib, the movable pulley and. a 4counterweight for balancing lthe weight of the jib pri'singa counterweight mounted upon the 4being provided upon the 'axis of the rollers. 5,. A crane according to claim 1, com-- guide member, thesaid counterwei ht be# l ing movable with and upon the sai guide members. 6. A jib'crane according to claim 1, comprisingfa counterweight movably carried by lthe guide.- member` 'for balancing the weighto f the jib, and a flexible member connecting `the said counter-'weight to the i 7. A jib crane according to claim 1, wherein a second guide member is rovided tocarry a counterweight for ba aneing the weight of the jib, and a second guiding surface is provided upon the jib for co-operat-J ing therewith.

' GUSTAV NIEMANN. 

